Can anyone test how it work with 5.1 and stereo sounds (s16, s24 broken ATM), especially if it remaps 5.1 channels correctly? 

I tested like this:

$ ./ffmpeg -i ~/matrixbench_highdivx_ac3.avi -c:v libx264 -s 160x120 -c:a pcm_bluray -mpegts_m2ts_mode 1 -sample_fmt s16 1.m2ts